I've written a post about this http://www.dodavinkeln.se/post/2012/02/09/cross-publishing-by-mirroring.aspx. There will be a follow up soon with a solution.
You have two options: Mirroring or PageProvider as I see it.
But I don't think there is a good solution regarding internal links.
Thanks for the link Johan,
Will have a read now.
Can I pleae have suggestions on the best way to replicate data on the same website, but between two different templates.
Using the fetch functionality, although working, will not suffice, as it ports over all of the content, but when you click on a link, it takes you back to the page in the other template...
Sorry if I havent explained very well, its almost a case of is 'internal mirroring' possible??